How to tell if kernel compiled from kernel.org is x86_64 or just 32 bit?

[john wendel]

On 06/21/2009 09:56 AM, Antonio Olivares wrote:
> Dear fellow Fedora users,
>
> Is there a way to tell if a kernel is 64 bit or 32 bit? If one compiles and installs a kernel from kernel.org.  Why am I asking?  I have a 64 bit Fedora 11 installed and it showed 2.6.29.4-???x86_64 at the end so I know it is a 64 bit kernel.  I copy the config of that kernel and compile a new one and install it, is that kernel still a 64 bit kernel or is it a 32 bit kernel?  When compiling I see just x86/ directories in the source of the kernel and no x86_64?
>
> I have a modem that needs drivers to con nect the modem is 32 bit only but can be compiled in 64 bit code, I tried without success compiling it against the 2.6.29.4-?? x86_64 kernel.  However, after compiling the kernel from kernel.org and compiling the same code it succeeded and it runs under the 2.6.30 kernel.  I know that `uname -a` will tell many things about our running kernels, but is there something else that can tell us?
>
> Or when we compile a kernel.org kernel, do we have to say compile it in 64 bit?
> I have compiled several kernels, but not knowing if the new kernel is indeed 64 bit or not?
>
> BTW:  Hope you have an excellent Father's Day!
>
> Regards,
>
> Antonio
>
>
>
>

If you build on a 64-bit system, the kernel will be 64-bit, same thing 
applies for 32-bit.

Regards,

John